1. Field of the Invention
This invention relates to a display unit having a plurality of display areas and a portable information terminal installing the display unit.
2. Description of the Related Art
In recent years, a display unit installed in a portable information terminal such as a portable telephone terminal has been ready for color display and further ready for moving image display. To support color display, power consumption is increased as compared with the current monochrome display and to support moving image display, moving image decoding newly becomes necessary and thus power consumption is increased as compared with the current still image or text display.
On the other hand, longer time is required as the standby time and the conversation time although the battery capacity has a decrease tendency with miniaturization of a portable telephone terminal.
To attempt to produce color display or display a moving image according to a display method in a related art, power consumption grows as compared with the current monochrome display and still image display. Thus, it is possible that an image is displayed only at the conversion time and operation time without displaying any image in the standby mode, thereby ensuring the standby time. However, for example, battery display, received electric field strength display, and the like need always be produced even in the standby mode, thus it is impossible to display no images in the standby mode.
It is therefore an object of the invention to provide a display unit and a portable information terminal capable of displaying a color image and a moving image while suppressing power consumption.
The display unit according to this invention comprises a display section that can be divided into a plurality of display areas, a power supply section that can selectively supply power to the plurality of display areas of the display section, a control section for outputting a selection signal for selecting the display areas of the display section and transferring display data classified in response to the display areas, a plurality of display data processing sections for converting the display data into a format fitted for the display area, and a data transfer path for separately transferring data from each of the display data processing sections to the display section, wherein an image of the display data generated by the display data processing section is selectively displayed in the display area of the display section based on the selection signal of the control section, so that power can be selectively supplied to the display areas of the display section in response to the display state, whereby power consumption can be suppressed.
According to the display unit of this invention, the display section is switched at least between a partial display area and a full display area containing the partial display area, so that the display area can be switched, whereby power consumption can be suppressed.
According to the display unit of this invention, the images of display data generated by the different display data processing sections are displayed in the plural display areas, and images in different formats can be displayed in the display areas based on the image data of interface specifications corresponding to each display area.
According to the display unit of this invention, display data is transferred on a slow data transfer period from the display data processing section to the display section for displaying an image in the partial display area and display data is transferred on a fast data transfer period from the display data processing section to the display section for displaying an image in the full display area or any display area other than the partial display area, so that the data transfer rate from the display data processing section to the display section can be changed in response to the display area, whereby power consumption can be suppressed.
According to the display unit of this invention, the data transfer path has signal lines a different number of which are assigned to the plural display areas, the display data is transferred via the signal lines, the number of signal lines can be defined in response to the display area, and the number of signal lines for transferring data to the display section can be reduced.
According to the display unit of this invention, a low frame frequency image is displayed in the first display area, a high frame frequency image is displayed in the full display area or any display area other than the partial display area, and the frame frequency can be changed in response to the display area, whereby power consumption can be suppressed.
According to the display unit of this invention, a low-gradation image is displayed in the first display area, a high-gradation image is displayed in the full display area or any display area other than the partial display area, and the gradation can be changed in response to the display area, whereby power consumption can be suppressed.
According to the display unit of this invention, display data is transferred on different data transfer periods in order from the display data processing section to the display section for displaying images in the full display area, so that the transfer period of the image data to be displayed can be changed whenever necessary, whereby power consumption can be suppressed.
According to the display unit of this invention, images different in frame frequency are displayed in order in the full display area, so that the frame frequency of the image to be displayed can be changed whenever necessary, whereby power consumption can be suppressed.
According to the display unit according to the invention, images different in gradation are displayed in order in the full display area, so that the gradation of the image to be displayed can be changed whenever necessary, whereby power consumption can be suppressed.
The display unit of this invention comprises a display section that can be divided into a plurality of display areas, a power supply section for selectively supplying power to the plurality of display areas of the display section, a control section for outputting a selection signal for arbitrarily specifying the display areas of the display section and transferring display data classified in response to the display areas, a plurality of display data processing sections corresponding to the specified image areas for defining at least one of data transfer period, frame frequency, and gradation of the display data corresponding to the specified image areas, and a data transfer path for separately transferring data from each of the display data processing sections to the display section, wherein images different in at least one of data transfer period, frame frequency, and gradation of the display data are displayed in the display areas of the display section based on the display data controlled in the display data processing sections, and the images different in format can be displayed in a plurality of display areas, whereby power consumption can be suppressed.
According to the display unit of this invention, the power supply section can supply different drive voltages to the display areas specified by the control section, so that the drive voltage of the display section can be changed partially, whereby power consumption can be suppressed.
According to the display unit of this invention, the control section specifies display or non-display for each of the display areas of the display section and the power supply section supplies power only to the area whose display is specified by the control section, so that power supply can be shut off partially, whereby power consumption can be suppressed.
According to the portable information terminal of this invention, an image is displayed in the first display area in the standby mode and an image is displayed in a full display area at the use time and the display area can be changed in the standby mode and at the use time, whereby power consumption can be suppressed.
According to the portable information terminal of this invention, display data is transferred on a slow data transfer period from the display data processing section to the display section for displaying an image in the full display area in the standby mode and display data is transferred on a fast data transfer period from the display data processing section to the display section for displaying an image in the full display area at the use time, so that the data transfer period can be changed in the standby mode and at the use time, whereby power consumption can be suppressed.
According to the portable information terminal of this invention, a low frame frequency image is displayed in the full display area in the standby mode and a high frame frequency image is displayed in the full display area at the use time, so that the frame frequency of an image can be changed in the standby mode and at the use time, whereby power consumption can be suppressed.
According to the portable information terminal of this invention, a low-gradation image is displayed in the full display area in a standby mode and a high-gradation image is displayed in the full display area at the use time, so that the gradation of an image can be changed in the standby mode and at the use time, whereby power consumption can be suppressed.
According to the portable information terminal of this invention, at least one of slow data transfer period, low frame frequency, and low gradation is set in a standby mode and at least one of fast data transfer period, high frame frequency, and high gradation is set at the use time and display data is transferred via as many signal lines as the number of signal lines complying with the corresponding data transfer format from the corresponding display data processing section to the display area, so that the data transfer period, the frame frequency, and/or the gradation of an image can be controlled in the standby mode and at the use time, whereby power consumption can be suppressed.